Computing scale



Dec. 20, 1938. P. M. COLE 2,140,984

GOMPUT ING SCALE Filed Dec. 18, 1956 6 Sheets-Sheet l INVENTOR 'Peul. M.Q a L E P. M. COLE COMPUTING SCALE Dec. 20, 1938.

Filed Dec. 18, 1956 6 Sheets-Sheet 2 A95 /3 f7 A93 053 A;

P. M. COLE COMPUTING S GALE Dec. 20, 1938.

Filed Dec. 18, 1936 6 Sheets -Sheet 3 INVENTOR 3 PAUL. M 001.2 BY MN 2 f20, p M; COLE COMPUTING SCALE Filed Dec. 18,,1956 6 Sheets-Sheet 6 Z Z 1E Z INVENTOR Y "Paul. M,.COLE

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Patented Dec. 20, 1938 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to improvements in computing scales and moreparticularly to that class of computing scales in which the apparatus isadjusted to a price per unit weight and a single total price isindicated.

It is an object of this invention to provide a scale which furnishes avisual unit price, weight and total price indication on two sides of thescale in a position to be read by, for example, both a merchant andcustomer and to provide a total price indicator, the subdivisions ofwhich will be of relatively large size and substantially constant, or ofthe same dimensions for the same variations in price and the same forall unit prices, and without sacrificing these objects to provide for alarge range of unit price to which the mechanism may be. set.

It is a further object of the invention to provide a computing scale ofvery small vertical height which will not obstruct the view of themerchant or customer and which may be conveniently used on highcounters, an object difficult to attain with most computing scales nowin use, in the majority of which a fan or drum type indicator carrying aseparate series of price indicia for each price per unit weight isemployed.

It is a further object of the invention to provide a computingmechanism, or mechanism adapted to multiply the weight of the mass beingweighed by the unit price, which will not be susceptible to shockthrough sudden movements of the weighing mechanism and will exert aconstant reaction against the weighing mechanism regardless of the unitprice to which it is set.

It is a further object of this invention to provide manually adjustablemeans for setting to difierent prices per unit weight, such that theprice setting of the computing mechanism will require little accuracy onthe part of the operator and will be accurate regardless of possibleslight inaccuracies in the price setting mechanism itself and require nolocking device for the weighing mechanism and enable the operator toplace the article on the scale before the setting is made or While thesetting is being made or after the setting has been made.

Other objects of the invention will appear more in detail in thefollowing description.

With these objects in view, the invention consists in a novel design ofa computing scale and its computing mechanism, the preferred embodimentof which is illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of a computing scale, showing thecustomers side of the apparatus;

Figure 2 is a rear elevation showing the merchants or operators side ofthe apparatus;

Figure 3 is a horizontal section taken on the 5 line 33 of Figure 1 andwith certain parts removed;

Figures 4 to '7 are vertical sections taken on the correspondinglynumbered lines of Figure 3;

Figure 8 is a plan view of certain parts of the apparatus omitted fromFigure 3 and showing certain portions of Figure 3 in phantom;

Figure 9 is a fragmentary section taken on the line 99 of Figure 3;

Figure 10 is a section taken on the line Iii-10 of Figure 8 showing theconstruction of one of the price setting riders; and

Figure 11 is a section through the price setting handle and taken on theline HH of Figure 4.

Referring particularly to Figures 1 and 2, the scale casing A isprovided on the customer's side (Figure 1) with the usual windows andhair lines (indicated at C, E and D) for the purpose of reading theprice per pound, total price and weight, respectively, from indicatingband C and indicating drums E and D, the operation of which is describedin detail below. On the merchants side similar windows for reading thetotal price E" and weight D" are provided, and also a manually operableprice setting handle G movable along a slotted tube F provided with unitprice indicia. The handle G may also be set to prices double thoseindicated in Figure 2, furnishing a very large range of priceadjustment. 35

A weighing pan B supported by four posts H is provided, and is connectedto the internal mechanism by these posts H and also by an adjustableplunger I.

Weighing system Theweighing pan B (see Figures 4, 5 and 7) is supportedby posts H which ride freely in sleeves I and are in turn suspended bystraps 3 from the arcuate ends 5 of four levers I, the inneit 45 two ofwhich are connected by cross pieces 2 and 4. (Figures 3 and 5.) At theopposite ends of members I (Figure 4) are provided knife edges 9 restingin V-blocks l I carried in stirrups l3 which are hung over the bars l5supported by brackets 50 ll affixed to the walls of the casing A.Springs 8 with lower ends attached to brackets H] are provided and serveto hold these knife edges down against the V-blocks. Springs 8 may alsobe used to compensate for any known deviation of 55 spring 29 fromHookes law by attaching springs 8 in the proper position below the knifeedges 9, as shown in Figure 4, since the connection of springs 8 may bemade such as to vary the movement due to their tension according to thepivotal position of arms Members 1 are pivotally connected by shafts E9,and the arcuate segments 5 at their ends are segments of cylindersconcentric about the axis of these shafts, serving to maintain parallelmotion of posts H, as straps 3 will be at all times tangential tosegments 5 and the portions of these straps suspending the posts Hvertical.

Attached to the two shafts I9 is a cross-piece 2| (Figures 3 and 7)having knife edges 23 resting in V-cut-outs 25 formed in a bifurcatedmember 21, the two ends of which are attached to springs 29 adjustablyfastened to the top of the casing A as by means of screws 3|.

Through this train of mechanism, the weight of pan B is supported bysprings 29, and a weight placed upon the pan will depress it and extendsprings 29 in direct proportion to the weight. Oscillation damping meansof any usual type, such as the air dashpot 32 attached to cross piece 2connecting two of the members I, may be provided.

Weight indicator Plunger I (Figures 3 and 5) is adjustably secured tothe under surface of pan B by a threaded rod 39 biased by a spring 30'and movable relatively to plunger I by a nut 32 which serves to providefor regulation of the zero of weight drum D. The rod 39 is rigidlyattached to pan B and may be provided with means such as the pin 3|protruding through slots 3| in the plunger I, to prevent rotation of theplunger I and twisting of the cable 6|, described below. This weightindicating mechanism comprises a drum D bearing weight indicia, andcarried by a vertical shaft 33 in bearings 35. Shaft 33 also carries agear wheel 31 driven by a rack 39 resting on rollers 40 and to the rackis attached an operating cable 4 Cable 4| in turn is attached to a pairof segments 43, 43 at the lower ends of bell cranks 45, 45' pivotallysupported by knife edges, 41, 41 in V-blocks 49, 49 on brackets 5|, 5|attached to casing A. The other ends of the bell cranks 95, 35 are alsoprovided with segments 55, 55', from which are hung weights 51, 5'! bymeans of the cables 59, 59'. Segments 43, 55 and 43, 55 are respectivelyconcentric about knife edges 41 and 4?. The weights 5?, 51 serve to keepcable 4| under tension and to bias the system toward counterclockwise(Figure 5) rotation of bell cranks 45, 45.

Also attached to segment 55 is a vertical cable 5| the upper end ofwhich is fastened to plunger I and which serves to connect thisindicating system to weighing pan B.

Weights 51, 51 are proportioned in relation to the length of the arms ofbell cranks 45, 45 so as to provide the bias above referred to, and itwill be apparent that this bias will be constant and unaffected bymovement of the indicating system. Variation in the moment due to motionof the center of gravity of the bell cranks 45, 45 may be avoided byplacing these centers of gravity at the edges of the knife edges 41, 41"or by placing these centers of gravity so that their moments about knifeedges 41, 41 are always equal and opposite.

Motion of pan B through this system will be communicated to drum D,producing an angular movement proportional to the linear motion of panB, and so indicating through windows D, D", the weight upon pan B.

Price indicating mechanism A drum E and windows E, E similar to thosejust described but marked with price indicia are provided (Figures 3,5-7, and 8). This drum is carried by vertical shaft (Figure 5) inbearing 13 and rotated through gear wheel 15 by a rack 11 resting onrollers 11 and to which is attached cable 19 fastened to segments 8|, 8|at the ends of bell crank levers 83, 83 carried by knife edges 85, 85'upon V-blocks B1, 81 supported by brackets 89, 89 from casing A. Theother arms of bell crank levers 83, 83 are provided with segments 9|,9|, these segments, as well as the segments 8|, 8| being concentricrespectively about the edges of knife edges 85, 85.

Segment 9| is advantageously made double (Figures 3 and 7) and a pair ofcables 93 attached thereto, these pulling upward on a yoke 95 adjustablysecured to a cross-piece 9! by means of a screw 99 threaded through yoke95 and rotatably fastened to cross-piece 91. Play may be taken up bysprings 98 drawing cross-piece 91 and yoke 95 together. An opening |D|in the top of the casing A and over the head of screw 99 is provided topermit adjustment of the distance between yoke 5 and cross-piece 9'! andthis adjustment serves to provide for regulation of the zero of totalprice drum E. Parts 95,, 91 are maintained in alignment by pins I03borne by the latter and riding in bores in the former.

This price indicating mechanism, similarly to the weight indicatingmechanism previously described, exerts a constant upward pull againstcross-piece 91,. regardless of the position of its parts and serves toconvert into a directly proportional angular movement linear movement ofcross-piece 91 by the computing or multiplying mechanism about to bedescribed. The bias for this price indicating mechanism is provided by aweight suspended by cable 92 attached to the segment 9|, alreadyreferred to, serving to keep cable 19 taut and bias bell cranks 83, 83toward clockwise rotation as shown in Figure 5.

Price computing mechanism Mechanism for moving cross-piece 91 in directproportion to the motion of posts H, multiplied by a factor proportionalto the price per unit weight for which the scale is set is provided andcomprises a system whose reaction against the weighing system isconstant regardless of the price per unit weight to which it may be set.

As best shown in Figures 6, 7 and 8, a pair of notched arms H9, I H! areprovided, pivoted at opposite ends by knife edges |l|, resting inV-blocks H2, H2 carried on brackets 5|, 5|. The other ends of these armsare supported by two of the posts H through rollers H5, H5 carried uponthe arms H0, H0 and resting upon steps I 15, l6 attached to the posts H.The depression of any given point along a line between the center ofroller H5 or US and knife edge IN or III will in consequence be directlyproportional to the depression of posts H and hence to the Weight uponweighing pan B.

The movement of these arms H0, H0 or, phrased more exactly, of linesalong them connecting their respective pivotal axes and the centers ofthe rollers H5, H5, is thus such that their slope varies proportionallyto movement of the weighing mechanism and in particular of the steps H6,H6. The variation in slope of these arms is thus directly proportionalto the vertical movement of any given point along their lengths andapproximates, where the angular movement of the arms is small, directproportionality to this angular movement.

Each of the arms H0, H carries a rider H1 or I I1, which can be movedalong its length and set in various fixed positions by means of shaftsH8 or H8 adapted to engage in any of the notches H9 or H9 along theunder side of arm H0 or H0, these notches being made so that shaft H8, II8 when in any notch has its center on a line between the center ofroller H5, H and knife edge III, III.

Price setting mechanism, later to be described, is provided and servesthe purpose of setting riders H1, H1 along arms H0, H0 so that they areoppositely positioned with respect to, and at the same distance from, acentrally located line. In the embodiment illustrated, in which the armsH0, II 0 are identically constructed and mounted, this will mean thatthe two riders H1, II 1 are at all times located at equal distances fromthe knife edges III., III, respectively, of the arms H0, H0.

Each of the riders H1, H1 is provided with a pair of rollers I20, I20mounted on shafts H8, H8 respectively. These rollers I20, I20 engagetracks I22, I 22 forming longitudinal members in a frame I2I andconnected by the cross members I23 of this frame to form a single rigidstructure. The two adjacent inner members I22, I22 of the frame I2I arepivotally connected to cross piece 91 previously referred to inconnection with the price indicating mechanism. Cables 93 will exert aconstant upward pull through cross piece 91 upon the frame I2I, urgingit against rollers I20, I20.

In consequence the vertical position of frame I2I will vary inaccordance with the position of the rollers I20, I20.

The vertical position of the riders H1, H1, due to the mechanism alreadydescribed, and more particularly the rollers I20, I20, will vary inaccordance with two factors: the position of arms H0, H0 themselves, andthe position of the riders H1, II 1 along these arms. As will beapparent, the depression of each pair of rollers I20, I20 when ridersH1, H1 are in a set position will be directly proportional (since theyare carried in a position on the beforementioned line between roller H5,H5 and knife edge III, III, upon arm H0 or H0, the free end of whichrests through roller H5 or H5 upon step H6 or H6 affixed to one of theposts H) to the depression of scale pan B and hence to the weight andalso to the indication of weight indicating drum D. The depression ofthese pairs of rollers I20, I20 will also be directly proportional totheir distances, respectively, from knife edges III, III about whicharms H0, H0 are pivoted. In the embodiment illustrated the parts are soproportioned and arranged that arms H0, H0, when no weight is uponweighing pan B, will be horizontal so that the price indicating drumwill remain at zero regardless of the position of riders H1, H1 uponarms H0, H0. The essential point of design in this particular is toinsure that each of the arms H0, H0 will be at right angles to the lineof motion of frame I2I when no weight is upon pan B.

Frame I 2! pulled upwardly by cables 93 through cross-piece 91 andstopped by rollers I20, I20 upon the four tracks I22, I22 will moveupward and downward in accordance with the position of rollers I20, I20as determined by the setting of riders H1, H1 along arms H0, H0 and theposition of arms H0, H0 controlled by the depression of posts H. Theresult is that the depression of frame I2I and hence of crosspiece 91 isdirectly proportional to the weight multiplied by the price per unitweight to which the mechanism is set, and so also is the angularmovement of price indicating drum E.

Since the motion of frame I 2I is rectilinear and rollers I 20, I20 areat all times oppositely located with respect to the pivotal axis ofcrosspiece 91 and at the same distance therefrom there is no variationin the reaction against the price indicating mechanism of the rollersI20, I20 and consequently no tendency of adjustment of riders H1, H1 todisturb the operation of the price indicating mechanism.

The net bias of the price indicating mechanism, produced by weight 90supported by cable 92 from segment 9|, as already described, is madeequal to the total weight of the two riders, allowance being made forthe weight of frame I2 I and attendant mechanism. Since this bias forcesthe frame upwardly against the rollers I20, I20 of riders Hi, H1 with aconstant thrust at all times, its only effect upon arms H0, II 0 is torelieve them of the weight of riders I I1, H1 and adjustment of theseriders will not vary the reaction of arms H0, H0 against the weighingsystem through the posts H, since the moment of each rider about thepivot point of its arm will at all times be canceled by a contrary equalmoment due to the bias.

With riders of relatively light construction and with relatively smallangular movement of arms H0, II 0 the location of the centers of gravityof the riders may be neglected without exceeding permissible limits oferror. Where the effect of this factor becomes sensible, its effect isnullified by constructing the riders H1, H1 so that their centers ofgravity are located axially of rollers I20, I20.

Price-setting mechanism Means is provided for moving riders H1, I I1 toset the machine to different prices per unit weight and is manuallyoperable by handle G to release the riders H1, H1 from the notches H9,H9 of arms H0, H0 and toreset them in different notches along these armscorresponding to different prices per unit weight.

The construction of arms H0, H9 and riders H1, H1 is the same, and itsuffices to describe in detail arm H0 and rider H1 with their attendantmechanism. Arm H0 is of channel iron shape, having depending flanges I30in which are formed the notches H9 already referred to (Figures 6 and Inthe interior of arm H0 is positioned a movable bar I3I, the function ofwhich is to disengage rider H1 from notches H9 and permit its movementalong the arm H0.

Rider H1 is formed of two telescoped parts of channel iron or U-shape,urged together by springs I38 passing through part I32 and over the endsof rollers I34. Part I32 carries the shaft H8 for rollers I20, and partI33 is provided with two rollers I34 which rest upon arm I I0. Part I32is provided with pins I35 riding in slots I36 in part I33 which serve tomaintain vertical alignment of the two parts of rider I I 1 whilepermitting a limited extent of relative movement vertically. An enlargedportion I 31 of shaft H8 engages in the notches H9 of arm H0 and i ofthe rider along bar IIO can take place.

downward movement of bar I3I will engage this enlarged portion I31depressing shaft H8 and part I32 of rider II1 to a point where enlargedportion I31 clears the notches I I9 and movement Correspondingly,lifting of bar I3I results in engagement of the rider with the nearestnotch I I9 upon bar IIO and sets the rider to the corresponding price.

Bar I3! being depressed and rider II1 consequently free to move, it isslid along arm IIO for price adjustment by means of a slide I40 havinglarge slots i4I through which passes the shaft H8. These slots are madelarge relative to the diameter of shaft IIO so as to permit the riderII? to seat accurately in the notch II9 immediately ahead of it when barI3I rises, and to eliminate contact between the price adjustingmechanism and the price computing mechanism when :once the adjustment ismade.

cranks 45 from brackets I41 attached to the flanges $36 of arm H0 and isbiased into upward or retracted position by spring I49 affixed to it atone end and bearing against a stop I5I upon the adjacent bracket I41.

Bar I3I is provided with a table I53, at its end bearing the knife edgesI I I and a U-shaped member I55 pivoted at I51 in brackets upon casing Abears a finger I59 adapted to engage tab-1e I53 upon rotation of theU-shaped member I55. This depresses the bar I3i, which swings downwardand toward the end bearing knife edges III (to the right in Figure 6)remaining parallel to arm IIO, under control of the cranks I45.

In operating the price adjustment handle G (Figures 4, 6 and 11) thehandle is slightly depressed, removing neck I63 of the handle, whichjoins it to a cylindrical slide I55 within tube I61, from a transverseslot I69 and bringing the neck I63 into registry with a longitudinalslot I1I extending the length of the price indicia bearing portion oftube i61. This motion frees the handle G for setting to the desiredprice, and also rotates the slide I55 and thereby presses a finger I13attached thereto against U-bar I55, depressing bar I3I, through fingerI59 and freeing rider I H, for movement along arm IIO. Transverse andlongitudinal motion of finger I13 is accommodated by a slot in tube I61similar to slot I1I but located underneath the tube and of greater widththan slot I1I. The actions of members I3I, II1 are the same as those oftheir corresponding members (I3I, Ii'i) the connection between the twosets of members being explained later.

The machine is now freed for price setting and this is accomplished bymoving handle G longitudinally along slot I15 until it comes oppositethe proper price indication. Attached to slide I65 is a continuous cableor chain I8I guided in a closed circuit by idler pulleys I83 and havingtwo courses directly over the arms H0, IIO. Attached to this cable arethe two slides I40 previously referred to which accordingly will moveriders II1, II1 along arms H0, H0 a certain number of notches which willbe the same as the number of price indications or correspondingtransverse slots H39 of the tube I61, along which the handle G is moved,the distance between the notches of arms H0, H0 being the same as thedistance between the slots of tube I61.

Along the courses of cable I8I which overlie the arms H0, H0 areprovided pairs of tracks I43, I43, each of the slides I40, I40 bearing apair of cross-pieces I42, I42 extending through the space between theupper and lower track of the corresponding pair of tracks I43 or I43.This construction serves to support slides I40, I40 slidably above armsI I0, H0 and maintain the slides I40, I40 in vertical position at alltimes.

Handle G, now being opposite the desired price indication, is raised orallowed to rise (due to a bias described below, into the correspondingtransverse slot I69 until finger I62 of slide I62 engages the top ofslot I69 (Figure 6). This removes fingers I59 and I59 from contact withtables I53, I53 releases bars I3I, I3I which are retracted within armsII 9, IIO' by springs I49, I49 and permits the enlarged portions I31,I31 of shafts I I8, I I8 to seat accurately in the notches H9, H9 underwhich they have been positioned approximately by the slides I40, I 48,eliminating all contact between the price setting mechanism and theremainder of the apparatus. Slots I4I, MI in slides I40, I40 are alwaysmoved to a position central with regard to a notch II9, i9. These slotsare wider than shafts I I8 as has been explained, so that regardless ofwhether riders IN, I I1 has been moved forward or backward shaft H8, H8in seating moves away from that side of the slot with which it was incontact during the adjustment.

Also attached to cable ISI is a band C, riding through a guide I93 inback of window C. This is marked with prices corresponding to those uponthe tube I61 and serves to indicate to the customer the price per unitweight to which the scale is set.

A greater range of price adjustment may be provided for withoutlengthening the tube I61 or slot HI and this may be achieved by a pricedoubling mechanism which doubles the indicated total price and doublesthe indicated unit price on the customers side of the scale. To employthis feature the machine is set for price per unit weight as before, butthe finger I61 of handle G is pulled back compressing the spring I64 andfreeing finger I62 from the slot I59 and the hendle is thrust upwarduntil finger I13 encounters the wall of slot I15. U-bar I55, due to abias to be described, will follow finger I13 and through arm 20Iattached to it pull up a shutter 202 which partly masks price indicatingdrum E, so that a second scale of prices double those normally displayedthrough the window E will be visible. Also attached to U-bar I55 is anarm 236 through which a similar shutter 208 is moved to double the priceper unit weight indication upon strip C visible through window C.Attached to U-bar I55 for rotation therewith is an oppositely extendingarm 2| I. Any rotation of U-bar I55 acts upon the abutment 2I2 of therectangular sectioned bar 2 I 5 which slides longitudinally in bearingscarried in brackets 2I4, 2 I4 of casing A, and abutment 2I6 at the otherend of bar 2I5 acts upon the arm 2II of U-bar I55 to rotate this U- baragainst the bias or spring 269 through an equal and opposite angle tothe rotation of U-bar I55.

The action of members I55, 20! and 202 in doubling the price indicationvisible through window E is duplicated, due to the cross connection justdescribed, by members I55, MI, and 202 on the merchants side of themachine so as to double the price indication appearing in window E.

Spring 209, already referred to, serves to bias arm I55,counterclockwise as shown in Figure 6,

and through the members, already described, con.-

necting U-bars I55 and I55, also biases U-bar I55 clockwise, providingthe previously mentioned bias for handle G and fingers I59, I59.

Operation While it is believed that the operation of the illustratedembodiment of the invention will be clear from the foregoing descriptionof its component mechanisms, for additional clarity certain features ofthe general mode of operation of the machine will now be reviewed.

The spring weighing mechanism comprises, as before described, a weighingpan B which is supported by posts H and through intermediate conneotingmembers depends from the springs 29, so that the extension of thesprings and, in consequence, the displacement of the pan B and attendantweighing mechanism, will be proportional to any weight placed thereon.In addition to the reaction of the springs 29, the weight indi eatingand computing mechanism reacts against the weighing system through theplunger I, and steps II6 carried upon two of the posts 1-1. Aspreviously explained, in connection with the description of the weightindicating mechanism and the price computing mechanism, the reactionagainst the weighing system will be constant and, hence, will not affectthe proportionality already referred to.

Depression of the scale pan B will have the eifect, through plunger I,cable GI, and segment 55 and its attendant mechanism, of rotating theweight indicator drum D, thus indicating the weight through windows Dand D. The computing mechanism, as previously explained, comprises meansfor moving riders II'I along the notched arms I III in accordance withthe setting of handle G to various price indications. Since, as beforeexplained, one end of each of the arms IIO, rests upon a step IIBcarried by one of the posts H, the depression of the riders II! will beproportional to the weight multiplied by the price to which the machineis set. In order, therefore, to furnish a total price indication it isnecessary only to impart to the total price indicating drum E a rotationproportional to the depression of the riders II'I. To eliminate anyvariation whatever in the reaction of the computing and total priceindicating mechanism against the weighing system the two riders I I1, III are employed. This permits the employment of frame I2I engagingrollers I29, IZII upon riders H1, H1, respectively, the employment ofwhich has important advantages. The attendant mechanism supporting frameI2I is such as to urge it upwardly with a constant thrust, regardless ofits position or the position of the total price indicating or pricecomputing mechanism. This upward thrust is made equal to the weight ofriders III, II? and, in consequence, merely relieves arms H6, H6 oftheir weight and will not produce a varying moment exerted against thearms in accordance with the position of the riders along them. It isalso necessary to prevent variation in the reaction of the ridersagainst the price computing mechanism and this result is achieved by theemployment of the symmetrically disposed riders, together with frameI2I, as previously described. The two riders being symmetricallydisposed about the point of support of frame I 2 I will exert a constantthrust against it regardless of their position along arms H0,

H0, and this is due to the fact that there is novariation in moment dueto movement of the riders but only a condition of balance which existsat all times and in which a variation in position of one rider is, ineffect, canceled by corresponding variation in position of the other.

The arms III], I ID, as previously described, act as levers, the pivotalaxes or fulcra of which are located at the knife edges III, the weightof the riders III, III being applied downwardly at points intermediatetheir ends and the supporting force being applied upwardly at theopposite ends of these levers through steps I I6 and rollers II5, whichconstitute means for displacing these levers so as to vary their slopeproportionally to movements of the weighing mechanism. The total priceindicating mechanism comprises in effect a balance consisting of theframe I2I, bell cranks 83, 83, weight 90 and various attendant parts, asalready described, by means of which the balance engages the riders III,III through its member I 2| and exerts at all times a constant thrustagainst these riders.

The function performed by riders III, III, as already described isdouble. They constitute primarily means for adjusting the points ofengagement of the balance (members I2I, etc.) with the levers III],III). They also serve the purpose of providing equal and countervailingmoments to neutralize any effect of the thrust of the balance exertedthrough member I2I upon the levers II I], III), which would otherwiseexist. In performing this latter function the riders III, III may beaccurately described as poises in the usual sense of the term althoughtheir eifect is not ultimately to displace the arms IIII, IIO but merelyto provide an adjustable bias for these arms by means of which theeffect of the bias of the price indicating balance system upon the armsmay be neutralized. It will be apparent that the two functions of theriders II I, II I, above referred to, are separable, but for convenienceof adjustment, I prefer to form the adjustable means for varying thepoint of engagement of frame I2I with the levers H0, H0 and theadjustable means for biasing the levers against the thrust of this framein a common member.

The weight of the riders II 1, H1 and the extent of adjustment providedfor along the levers IIU, III), will, of course, depend upon the thrustexerted by frame I2I against the levers. This is a factor which can varywidely depending upon the size of the machine generally, the type ofwork it is intended to do, the permissible error, and the weight andfrictional characteristics of the price indicating dial and itsassociated mechanism. As a limiting case the weight of the riders H1, H1may be negligible so that they function not as a bias but merely asadjustable means for varying the points of engagement of the priceindicating balance with the levers III], II c. This limiting case willbe approximated where the bias of the price indicating balance inrelation to the magnitude of the quantities to be dealt with by theweighing mechanism is so small that variation in the reaction of theprice indicating balance against the weighing system is negligible andfalls Within the permissible limits of error of the machine as a whole.The limiting case would be realized where the price indicating balancehas no net bias but constitutes merely a balance system adapted to remain in whatever position it is set and in this case it will, of course,be necessary to employ some suitable form of connection between thebalance system and the levers at the points of engagement.

It will be understood that where in the foregoing specification I havereferred to a bias as constant, or to various distances as proportion orequal, or to a precise relation between certain angles and directions ofmovement, and the like, that such statements must be taken in apractical rather than a theoretical sense. It is a great advantage inthe apparatus of my invention that extremely accurate and complicatedmachining of parts is largely avoided so that the design of the machinemay be kept within extremely small limits of error and still provide forpractical tolerances of commercial manufacture. The practical toleranceswill, of course, vary somewhat widely in accordance with the Work forwhich the machine is designed and it will be found in many cases thatquite wide deviations from exact relationships may be introduced withoutexceeding permissible limits of error.

The lacks, pinions, and drums of both the price computing mechanism andthe weighing mechanism are acted upon by the respective bias of eachsystem and never directly by pan B. Any sudden loading or unloading ofpan B will hence not transmit shock to these members, the maximum speedof which is determined only by the magnitude of the bias and theproportions of the parts. Price and weight drums of greater diameter andmoment of inertia than would otherwise be possible may thus be usedwithout increasing the wear of racks and pinions.

From the foregoing description it will be apparent that a computingscale has been provided in which proportional movement of weightindieating and total price indicating parts is achieved withoutvariation in the reaction of the con puting and weighing systems againsteach other, regardless of the price per unit weight to which themechanism may be set, and that this result, moreover, is attained withgreat simplicity and reliability of construction.

It will be apparent also that various of the mechanisms described and,in particular, the price computing and total price indicating mechanism,in addition to being capable of conjoint use with the otherinstrumentalities described, are also adaptable to use with differentinstrumentalities for performing similar functions.

What is claimed is:

1. In a computing scale, and in combination, displaceable weighingmechanism, a pair of levers, means for varying the slope of said leversproportionally to displacements of said mechanism, a price indicator,movable means for engaging both said levers, means for deflecting saidprice indicator proportionally to displacements of said movable means,and adjustable means for causing said movable means to engage each saidlever at points along its length at predetermined distances from itspivotal axis.

2. In a computing scale, and in combination, displaceable weighingmechanism, a pair of levers, means for varying the slope of said leversproportionally to displacements of said mechanism, a price indicator, amovable member adapted to engage both said levers, means for deflectingsaid price indicator proportionally to displacements of said member andadjustable means for causing said member to engage each said lever atpoints along its length at predetermined distances from its pivotalaxis.

3. In a computing scale, and in combination, displaceable weighingmechanism, a pair of levers, means for varying the slope of said leversproportionally to displacements of said mechanism, a price indicator, amovable member adapted to engage both said levers, means for deflectingsaid price indicator proportionally to displacements of said member,adjustable means for causing said member to engage each said lever atpoints along its length at predetermined distances from its pivotalaxis, a constant bias for urging said movable member in a predetermineddirection toward said levers, and adjustable means for biasing saidlevers toward said member.

4. In a computing scale, and in combination, displaceable weighingmechanism, a pair of levers, means for varying the slope of said leversproportionally to displacement of said mechanism, a poise carried oneach of said levers, said levers being so proportioned and arranged thatsaid poises when set at equal distances from the respective pivotal axesof said levers are symmetrically located with respect to a predeterminedline, a balance adapted to engage said poises, said balance having aconstant net bias equal to the combined weight of said poises, a priceindicator, and means for deflecting said indicator proportionally todisplacement of said balance.

5. In a computing scale, and in combination, displaceable weighingmechanism, a pair of oppositely extending levers pivoted for rotation inparallel planes, means for varying the slope of said leversproportionally to displacement of said mechanism, a poise carried oneach of said levers, a balance adapted to engage said poises andmoveable in a predetermined direction, said balance having a constantnet bias in said direction equal to the component in said direction ofthe combined weight of said poises, a price indicator, and means fordeflecting said indicator proportionally to displacement of saidbalance.

6. In a computing scale, and in combination, displaceable Weighingmechanism, a pair of oppositely extending levers pivoted for rotation inparallel planes, means for varying the slope of said leversproportionally to displacement of said mechanism, a poise carried oneach of said levers, means for adjusting said poises along said leversto positions equidistant from the pivotal axes of said levers andsymmetrically located with respect to a predetermined line, a balanceadapted to engage said poises and movable in a predetermined directionparallel to said line, said balance having a constant net bias in saiddirection equal to the component in said direction of the combinedweight of said poises, a price indicator, and means for deflecting saidindicator proportionally to displacement of said balance.

PAUL M. COLE.

